2. Geothermal energy is the earth’s natural heat available
inside the earth.
This thermal energy contained in the rock and fluid that
filled up fractures and pores in the earth’s crust can
profitably be used for various purposes.
Geothermal energy is an enormous, underused heat
and power resource that is clean (emits little or no
greenhouse gases), reliable (average system availability
of 95%), and homegrown (making us less dependent
on foreign oil).
3. Geothermal energy is defined as heat from the Earth.
It is a clean, renewable resource that provides energy
in the U.S. and around the world in a variety of
applications and resources.
4. 1. Space/District Heating: Schemes utilizing geothermal heat
provide over 80% of the central heating needs of Reykjavik
city in Iceland and are employed in many towns in USA,
Poland and Hungary.
2. Agriculture and Aquaculture: In temperate and colder
climates, greatly improved plant and fish growth can be
achieved by heating soils, greenhouses and fish ponds using
geothermal heat.
3. Power Generation: With over 8000 MW of installed capacity,
geothermal electric power generation is a well-proven
technology that has been especially successful in countries and
islands that have a high reliance on imported fossil fuels
(World Bank Group, 2004).
5.
6. Costs for geothermal electricity generation are 4.5-7 cents per
kilowatt-hour. This is competitive with some fossil fuel
facilities, but one must keep in mind the drastic reduction of
pollution.
Delivered costs depend on ownership arrangements, financing,
transmission, the quality of the resource, and the size of the
project.
Geothermal plants are relatively capital-intensive, with low
variable costs and no fuel costs.
8. Liquid-dominated plants
Liquid-dominated reservoirs (LDRs) are more common with
temperatures greater than 200 °C (392 °F) and are found near
young volcanoes surrounding the Pacific Ocean and in rift
zones and hot spots.
Thermal energy
Lower temperature sources produce the energy equivalent of
100M BBL per year. Sources with temperatures from 30-150 C
are used without conversion to electricity for as district heating,
greenhouses, fisheries, mineral recovery, industrial process
heating and bathing in 75 countries.
9. Enhanced geothermal
Enhanced geothermal systems (EGS) actively inject
water into wells to be heated and pumped back out.
The water is injected under high pressure to expand
existing rock fissures to enable the water to freely flow
in and out.
10. It is a renewable source of energy.
By far, it is non-polluting and environment friendly.
There is no wastage or generation of by-products.
Geothermal energy can be used directly. In ancient
times, people used this source of energy for heating
homes, cooking, etc.
11. Only few sites have the potential of Geothermal
Energy.
Most of the sites, where geothermal energy is
produced, are far from markets or cities, where it needs
to be consumed.
Total generation potential of this source is too small.
There is always a danger of eruption of volcano.
12. The future of geothermal energy depends on three
factors: it’s demand, supply and it’s competitiveness
among other renewable resources in terms of cost,
availability, reliability etc.
13. Geothermal energy is limited in extent as extracting the
heat usually exceeds the replenishment rate
Hot, dry rock (HDR) is widespread and offers new
resources in areas where geyser activity is unknown
Direct low-temperature heat transfer for home systems
is practical as long as low maintenance is designed into
the system
Sources of high temperature water or steam are limited
and the cost of extraction, maintenance, and operation
will remain high in comparison with other sources of
energy
